<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <select placeholder="123" name="" id="" onchange="ma(value)">
        <option value="" id="ma">请选择爱好</option>
        <option value="a" >篮球1</option>
        <option value="b">篮球2</option>
        <option value="c">篮球3</option>
        <option value="d">篮球4</option>
    </select>
    <select name="cars">
        <option selected hidden disabled value="">点击选择你想要的选项</option>
        <option value="saab">Saab</option>
        <option value="fiat">Fiat</option>
        <option value="audi">Audi</option>
    </select>
    
    <input type="text" placeholder="aaa">
  <script>
       
       var  info={hobby:'a'}
      
         document.querySelector('#ma').value='a'
         document.querySelector('#ma').innerHTML='篮球1'
       function ma(a){

        console.log(a);
       }
      
       document.querySelector('.ma')[0].set


          
     
  </script>


</body>
</html>